Abstract:Phytoestrogen （PE） is a type of plant component that is widely found in traditional Chinese medicine and has similar bioactivity of estrogen. It has been widely acknowledged about the role of phytoestrogens in the prevention and treatment of cardiovascular diseases，osteoporosis， tumors，and improvement postmenopausal syndrome in women. In recent years，more and more studies have shown that phytoestrogens play a protective role in the prevention and treatment of Alzheimer’s disease. Because they are widely derived from plants，and have no obvious side effects，concomitantly can be used as preventive health products，making phytoestrogens have a wide range of applications and prospects. This text reviews the source，classification，biological activity of phytoestrogens，and their pharmacological effects on improving learning and memory function， reducing the production of β-amyloid，antagonize the toxicity of β-amyloid and enhancing the function of cholinergic neurons ，the anti-oxidative stress and the neuroprotective effect in eliminating free radicals in Alzheimer’s disease，as well as the mechanism of phytoestrogen exerting neuroprotective effect through direct genomics and non-genomic effects. It provides new ideas and strategies for the development of Alzheimer’s disease prevention and treatment drugs making it a promising alternative to estrogen.

Key words:phytoestrogen,selective estrogen receptor modulators,estrogen,Alzheimer&rsquo,s disease